In order to investigate the effect of local meteorological
conditions on pollen emission, taking into account that the
pollen source, i.e. the tassels, are located at the canopy height,
the pollen concentration at z/h = 1 was taken as a surrogate for
pollen production (source strength). The diurnal variation of
canopy height pollen concentration is depicted in Figs. 8–10 as
horizontal bars whose widths indicate the time span over
which the data was collected together with temperature T,
relative humidity RH, solar irradiance S, and mean velocity U,
that were measured by the NOAA weather station